LU-12518 llite: rename count and nob variables to bytes

LU-12518 llite: rename count and nob variables to bytes

Rename "*count", "*nob", and "cnt" and similar variables to use
"*bytes" to make it clear what the units are vs. number of pages.

Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I195f2db4182e4b3099b3f4aa2e25b91f9f3ebbe5
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/38154
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>